Guest Post By: Dave Callan, P.E., Senior Vice President, Chicago-based McGuire Engineers

Building owners and operators face many challenges when re-opening commercial facilities post-COVID-19. Add the risk of Legionella bacteria and you’ve got the potential for a compound disaster.

A multi-stage domestic water pumping system which delivers potable water to high rise buildings.  As the hot water heaters are exercised, and all of the outlets have been cleaned and sanitized, these pumps will begin ramping up to meet demand and provide the clean chlorinated water required to operate safely.  

A bacterium that causes a pneumonia-like illness called Legionnaires’ disease, Legionella grows in the still waters of cooling towers, hot water heaters, fountains, faucets and showers when plumbing systems are left stagnant, or underheated. Commercial buildings that failed to run the water while unoccupied or shut down their HVAC systems to reduce energy bills are ripe for bacteria growth.

Both COVID-19 and Legionella are transmitted through aspiration. COVID-19 is aspirated via an exchange of air between humans, while Legionella is aspirated via water. Without traditional safeguards including continuous movement and cleansing of water and maintaining 120 to 140-degree building water temperatures, Legionella can spread to water droplets small enough to breathe in and infect occupants.

When re-opening a facility, building owners and managers must consider each and every faucet, hose bib, tenant humidifier, fountain and shower head as a possible Legionella infection source. Consider these 6 TIPS to making the return to work a safe one for all occupants.

1.     Flush out all fixtures completely. Bathroom faucets, kitchen sinks and showers will carry the biggest potential for infection spread. Flush the plumbing system completely with new cold water to replenish the residual chlorine in the system. Once the systems have been flushed, temporarily increase the temperature of the hot water heaters to 140 degrees.  Then run each fixture again with full hot water for 5 minutes to kill any remaining bacteria. Apply this to every bathroom and kitchen faucet, shower in the building’s gym, hot tub and spa as well as lobby fountains. Make sure that building engineering and maintenance personnel wear a mask and gloves when draining and refilling to protect themselves from exposure to pathogens.

2.     Next, test them. As soon as the hot water heaters have been up and running for 48 hours, begin spot testing for Legionella bacteria in multiple locations. Legionella testing kits have a quick return, providing accurate results in just two hours. Retain the results for your records to minimize your liability. Should an occupant get sick, you’ll need the records to defend a claim against your property or management company.  

3.     Do it in enough time. Running faucets a few hours before tenants return isn’t enough. The goal is to flush fixtures  out multiple days, or at a minimum 48 hours, before occupants are scheduled to return. This means closely following the governor’s order in each state and preparing accordingly.

4.     Reduce or eliminate point of use aerators completely. There’s a reason aerators aren’t used in hospitals – they retain bacteria at the spout. Aerators pull air in and mix it with water in an effort to reduce water use while still delivering the same feel to building occupants. When turned on, an aerator will spray whatever is in its point-of-use spout, including bacteria, into the air and onto the sink or faucet users.Select laminar flow faucets instead. These plain spout fixtures dry completely after each use.

5.   Extend timing of automatic faucets. Touchless faucets are ideal for reducing the spread of bacteria on handles, but they only run water for five seconds, not the 20 required to prevent the spread of infection.That 5 seconds isn’t enough to demand hot water either – also a critical tenant of infection control. While it’s possible for occupants to re-engage the faucet, most won’t do it the four times it takes to reach 20 seconds of washing. Reset your building’s automatic faucets to run for longer and reach a higher water temperature earlier.

6.     Move forward with precaution. Building operators and maintenance personnel will want to establish protocol instituting these best practices as regular maintenance moving forward. Include daily faucet runs and monthly Legionella testing to keep your facility free of viruses and bacteria. Increase these strategies at the beginning for as long as your facility is running at partial load with reduced occupants. Make sure hot water heater temperatures are set to manufacturer recommended values and that staff is outfitted with masks and gloves when running faucets and testing.

Preventing COVID-19 and Legionella in the Workplace

Early symptoms of COVID-19 and Legionnaires’ disease are similar, and because infection in both cases comes from aerosolization, building occupants that come down with a cough or fever may mistakenly assume they’ve contracted one or the other. Misdiagnosis could lead to increased liability for building owners and operators.

Employing these best practices will ensure that you’ve done everything you can to prevent building aerosolization of pathogens and yet they aren’t a cure all for infection prevention. Hang signs around public and bathroom sinks reminding occupants and tenants to continue washing their hands regularly, wearing masks and minimizing surface contact as much as possible.

Dave Callan, P.E. is Senior Vice President, Chicago-based McGuire Engineers